Ashp1989

iTrader: (1)

Hi. My car has just gone into the bodyshop today for quite abit of paint and rust sorting and my sills being repaired. It's a v5 type r. When I get it back I'm wanting to get underneath and underseal or wax oil it!
The thing is, is that I'm not sure what to do? Do I rub down underneath the car the just underseal it? Or just wax oil it? Or both? And in what order? Cheers. Ash

topshot

iTrader: (4)

I rubbed any rusty areas right back to clean metal then rust treated it with Hydrate 80 and then painted it with normal car paint (black). I then coated the whole underbody/arches with Hammerite underbody sealant.

Its important you clean up rusty areas before undersealing and make sure everything is clean/dry.

Ashp1989

iTrader: (1)

Thanks for that info. Was the undersealant spray or brush applied? What did u rub down with? Wire brush?

Worlasshasansti

Wire wheel in a drill/grinder will save loads of time and elbow grease.

I would get a few opinions from people who work in the trade as I've heard numerous things over the years about what's best etc, I was told that the undersells which set like hard rubber stuff can retain water and actually rot your car quicker lol.

I've always used waxoyl myself but never had to do a full chassis, I've heard of people using the Schultz spray stuff with a compressor but can't comment on that myself.

Mick

codfather

iTrader: (1)

My method is any areas underneath the car where the original underseal has split, sand it back to bare metal then red oxide paint that area..finally when the paint has dried get the waxoil on it (2 good coats is preferred)

Donnie Brasco 46

iTrader: (2)

I've always been told if you rub the paint back to bare metal to apply zinc to it before reprinting/under sealing.

Ashp1989

iTrader: (1)

Think il just do what codfather said. Rub back any metal and red oxide it then apply wax oil. Not actually had a look underneath, just that my sills are goosed that's y they are getting replaced, so I'm guessing that there will be abit of surface rust underneath, I'm hoping that's all ther is lol.

topshot

iTrader: (4)

This is the wax/underseal to use, it stays flexible so won't crack and let water in. Just brush it on once the underside has been cleaned and painted

http://www.halfords.com/webapp/wcs/s...egoryId_165594

quattroowner

iTrader: (5)

A wire wheel on a drill and a grinder , get any flaky stuff off and any area's that are susceptible to water ingress ( Arches, sill's ,boot floor)

Red oxide primer ( 2 layer's) 2nd coat when it's gone quite tacky and nearly dry.
now the expensive stuff!! POR 15 (Frost) . It is expensive stuff but it's by far and away the best stuff to use. Used it myself and other's and it's certainly the most durable out there.

Best to do the whole underneath to really get the full protection, dont forget to use seam sealer on any joins or panels gaps first.

If you get hold of some decent flexible primer that is use able on rubber or plastic. You can spray over it , paint the colour of your choice. and voila. . a well protected underneath and also colour coded

Just make sure it's done in a dry area, and underneath is completely dry before hand

Ashp1989

iTrader: (1)

Seam sealer? Never really thought or heard of that. Just an example where would you pAint this stuff onto? And does it go on after the waxoil/underseal? Or before?

topshot

iTrader: (4)

Seam sealer is used for any joins where the panels meet each other. It will have factory stuff on there which maybe ok onyour car unless you can see rust around the panel joins. It goes on before any paint/waxoyl.